This invention relates to chain-link types of cable carriers, usable for example for surrounding, carrying and protecting flexible conduits of air, hydraulic fluid, or electricity; typically such carriers are used to contain wires, electrical cables or hoses for conveying fluids. As used herein, the term "cable" will be understood to include any elongated flexible object or group of objects which is to be contained within, and extend along the length of, the interior of the cable carrier.
Such carriers typically comprise a plurality of "links" pivotally connected to each other end-to-end in a series chain, so that each link can be articulated or pivoted with respect to its neighbor and the carrier thereby enabled to flex easily and assume various curvilinear configurations, at least in a given plane of flexing, so as to accommodate corresponding required flexure of the flexible cable. In one typical application of the invention, for example, one end of the cable carrier may be clamped to a stationary portion of a metal-working machine and the other end secured to a reciprocating part of the machine which moves in the plane in which the cable carrier is designed to flex; an electrical cable which is necessary to the operation of the machine may extend between the stationary and reciprocating parts thereof, and passes through the cable carrier so as to be protected by it and held from pivoting randomly sideways.
Various types of cable carriers have been proposed in the past, some of which have found use. See for example the following U.S. Pat. Nos.: 3,772,875 issued Nov. 20, 1973 to L. Viano; 3,921,388 issued Nov. 25, 1975 to K. Loos; 3,664,619 issued May 23, 1972 to K. Heidrich et al.; 3,448,954 issued June 10, 1969 to S. Kurlandsky; 3,053,358 issued Sept. 11, 1962 to A. Gross; 3,188,795 issued June 15, 1965 to R. Ulm; 3,779,003 issued Dec. 18, 1973 to M. Boissevain et al.; 3,284,036 issued Nov. 8, 1966 to H. Nansel; 2,899,159 issued May 28, 1956 to W. Leblang; as well as French Pat. No. 1,270,041 issued July 17, 1961 to E. Constantin and British Pat. No. 821,182 issued Sept. 30, 1956 to M. Manne.
In a cable carrier it is often desirable to enclose the carried cable substantially completely, in all of its flexed and unflexed configurations. For example, the cable and carrier may be used in an environment in which metal shavings are present in the immediate ambient, which if they enter partly or completely into the carrier may damage the cable or interfere with operation of the carrier.
It is also desirable in general that the interior of the carrier be quite smooth, so as to permit easy relative motion between cable and carrier without damage to the cable or carrier during flexing.
Also, it often occurs that pinch points exist at one or more positions along the inside of the carrier, at which points the cable may be subjected to substantial pinching effect due to articulation between the links, particularly in the regions between the links. Elimination or minimization of such pinch points is of course also highly desirable.
It is further desirable in many applications to limit the angle of pivot between adjacent links, usually in both directions. Thus, it is usual that the cable is to be bent or flexed from its normal unstressed configuration only to a limited extent, lest it be permanently deformed, broken from fatigue due to repetitive overflexing, or bent so sharply in the case of a fluid-conveying conduit that the desired flow may be cut off or greatly reduced by undue flexing of the conduit. In certain applications it is also desirable that the limit of articulation in one direction be at or about 0.degree., whereby the carrier will assume a substantially straight-line configuration at one extreme of flexure, with all of the permitted flexing of the carrier being in one angular sense only. An arrangement of this type will be described in detail hereinafter.
In general, it is also usually desirable that the links be easy and inexpensive to fabricate and easily assembled to, and disassembled from, their neighbors, so that different lengths of the chain type carrier can be readily provided for different applications.
The problem of maintaining a substantially complete enclosure of the cable within the carrier is particularly difficult to overcome, since the articulation of one link with respect to its neighbor typically causes one link to pivot away from its neighbor, leaving a very substantial gap which exposes the interior to harmful ambient materials and conditions.
It is therefore an object of the present invention to provide a new and useful chain-link cable carrier, and a new and useful form of link for use therein.
A further object is to provide such carrier and link which provide substantially complete enclosure of the cable contained therein, even when it is flexed.
Another object is to provide such carrier and link which minimize the chances of pinching of the cable when the carrier is flexed.
A still further object is to provide a cable carrier and link which presents a substantially smooth interior to the cable therein.
A further object is to provide such a cable carrier and link which can be molded in one piece.
It is also an object to provide a cable carrier and link in which the links can readily be assembled to, or disassembled from, each other.
Another object is to provide such cable carrier and link which provide predetermined limits for the flexing thereof in both directions of angular flexing.
It is also an object to provide such flexing limits so that flexing in one angular direction is limited at about 0.degree., in which position the links are arranged along a substantially straight line configuration.